Induction heating systems apply an AC electric signal to a conductor adapted to produce a magnetic field, such as a loop or coil. The alternating current in the conductor produces a varying magnetic flux. The conductor is placed near a metallic object to be heated so that the magnetic field passes through the object. Electrical currents are induced in the metal by the magnetic flux, and the metal is in turn heated by the flow of electricity induced in the metal by the magnetic field.
Because high current AC signals are transmitted through the cables in an induction heating system, it is necessary to cool the cables during operation to prevent overheating and damage to components. Air cooled systems can be used in heating applications of about 400 degrees or less. When the application is intended to heat the metal to a temperature over 400 degrees, liquids are typically used to cool the system.
Liquid coolants provide a higher degree of thermal transfer away from the cables, but are difficult to use for a number of reasons. For example, liquid coolants require additional equipment, including cooling units with pumps for circulating the coolant. More importantly, routing the coolant through the system and adjacent to the electrical wires can be difficult, particularly in high power applications.
Present systems typically use T-fittings for connecting a hose from a cooling unit to a cable bundle that includes both the current-carrying electrical cable, and the cooling fluid. Here, when extensions are required, a jumper is used to route the fluid flow around the connection area, as described in U.S. Pat. Nos. 8,038,931, and 7,696,458 which are hereby incorporated by reference in their entirety for the description of an induction heating system and associated cooling system. While this system is effective in providing appropriate cooling of the cable, the bends in the T-fitting undesirably restrict coolant flow, and there are hot spots where the connections are made.
Other systems run coolants directly through the electrical connection. These systems do not include a shut off or quick disconnect, and coolant drips out of the cables when they are disconnected, wasting coolant.
There is a need therefore for an improved electrical and fluid connector, and corresponding induction heating system that avoids the problems associated with current induction heating systems and cabling. The disclosed system addresses these and other issues.